| Abstract: | A Sward rocker tester is used to obtain the Sward number for glass, mild steel, copper, poly(methyl methacrylate), polyethylene of various densities, and natural rubber. A relationship between the number and mechnical properties is investigated. It is shown that with metals and glass the number is essentially a frictional factor. With plastics and rubber it is a true hardness factor, involving dynamic Young's modulus, Poisson's ratio, and damping capacity. The aim of the investigation is to encourage the development of the Sward test as a nondestructive quality test for plastics. |
